gridLevelPerColumn property
The meaning of this has been lost in the sands of time: it still exists as a property, but appears to be unused in the modern UI of talent grids. It used to imply that each visual "column" of talent nodes required identical progression levels in order to be activated. Returning this value in case it is still useful to someone? Perhaps it's just a bit of interesting history.
Implementation
@JsonKey(name:'gridLevelPerColumn')
int? gridLevelPerColumn;